1. Field of the Invention
The present invention relates to an operating method implemented through a user interface, and more particularly to such an operating method for a computed tomography examination procedure.
2. Description of the Prior Art
Computed tomography is referred to as CT for short. Different from traditional x-ray imaging, CT employs an x-ray beam to transversely scan a certain region in the human body slice by slice to acquire a certain amount of slice information, which is processed by a computer to obtain a reconstructed image. Such a reconstructed image is referred to as a transverse anatomical image, and can be further processed by the computer to obtain a three-dimensional reconstructed image.
CT, in terms of its external structure, basically embodies a gantry, a patient table and a computer system. The gantry basically includes a high-voltage generator, an x-ray tube, a radiation detector and a data acquisition system. The high voltage generator generates a high voltage for use with the x-ray tube. The x-ray tube and the radiation detector are mounted on opposite sides of tissue to be scanned, facing each other. The x-ray tube generates x-rays and the radiation detector receives the projection information produced by the x-rays transmitted through the human body. Based on the fact that x-ray absorptions of various human tissue (including normal and abnormal tissue) are different, CT divides a certain selected slice in the human body into a number of small cubic blocks of the same volume, referred to as voxels. CT employs an x-ray beam to scan a slice of a certain thickness in a certain region in the human body to obtain projections at different angles, and uses convoluted back projection (also known as filtered back projection) algorithms to reconstruct a tomographic image of the tissue in said region. Each point of the image is represented by a CT value (having a unit of Hu (Hounsfield Unit) corresponding to an attenuation coefficient of different tissue. This point is a basic unit of a CT image and referred to as a pixel. All pixels of an image are arranged in rows and columns, which form an image matrix and thus a CT image.
When an operator uses a CT scanner to examine a patient, a series of operations are to be performed on the CT scanner. Since x-rays from the CT scanner may cause damage to the patient, for safety, the operator should reduce mis-exposure due to various incorrect operations as far as possible. In order to learn how to operate the CT scanner, the operator is generally required to read the user manual of the CT scanner. However, the CT scanner is a complex system, and thus it often takes several weeks or even longer for a novice operator to learn to examine the patient skillfully. Therefore, an intelligent and legible user interface is necessary for the operator to shorten the time he/she spends in learning to operate the CT scanner skillfully, thereby improving operational efficiency and hence shortening time spent in examining each patient.
An examination procedure for the CT scanner typically includes several steps as shown in FIG. 1: registering a patient, positioning the patient on the patient table, selecting a scanning scheme, scanning a scout view, making a tomography scanning plan on the scout view, performing tomography scanning, and ending the scanning.
A display screen for the CT scanner is generally divided into four areas. In FIG. 2, which shows a prior art screen, there is a scout view area at top left, a tomographic image area at top right, a workflow list area at bottom left and a parameter setting area at bottom right. Prior art high-end products (such as Siemens SOMATOM Emotion and Sensation series) allow the operator to select one or more scanning programs (also known as scanning schemes or examination schemes), and thereby to scan multiple regions or scan one region multiple times using different programs. However, CT scanners of this type have the disadvantage that there is no logical sequence relationship between the menu items (such as registration, program, breath prompt and end in FIG. 2) and the options (such as scout view, and scanning one, scanning two, . . . , scanning N in FIG. 2) in the workflow list at bottom left. In other words, the operator, after completing the previous step, will not be quite sure of what to do next due to the fact that the interface fails to provide explicit indication thereof. This will give the operator, especially an inexperienced operator, some difficulty. If the operator unfamiliar with the operating steps operates incorrectly, he or she must make corrections, which is time wasting and thus reduces operational efficiency. Another type of low-end CT scanner (Siemens SOMATOM Smile) of the prior art solves the above-described problem of lack of logical sequence relationship between the menu items and the options by merging the menu items and the options into a list of options, as shown in FIG. 3. However, it is not capable of loading multiple scanning programs, and the operator can choose only one scanning program each time to scan, which lowers operational efficiency.
An operating interface for the CT device that not only enables the operator to operate using only one list of options but also allows scanning of multiple regions in the human body is desirable. Such an operating interface, suitable for scanning multiple regions, is different from the one suitable for scanning only one region as shown in FIG. 3. A substantial modification to the software architecture is needed because a slight change in the interface, sometimes even a change of one option or button, may lead to corresponding alteration of the entire software architecture.
When operating the CT scanner, it is very important to enter a correct patient posture so as to display correct directions (such as up or down, and left or right) on a CT image. In prior art, when the patient posture is to be determined (eight different postures to be selected, depending on head first or feet first, lying supine or lying prone, and left lateral position or right lateral position), the determination is made by clicking at least twice with the mouse at the control console (user interface). However, according to an investigation, for each hospital, if the regions to be examined are identical, the postures of different patients are consistent in most cases whereas inconsistent only in very few cases. Therefore, if each time substantially the same patient posture is to be selected, the number of clicks is unnecessarily increased, lowering operational efficiency. This problem tends to be more severe when there are many patients to be examined.
Besides, during operation, the operator needs to decide whether to perform automatic reconstruction, automatic transfer and automatic filming. Since there are relatively many selected parameters, sometimes the operator may forget whether said automatic reconstruction, automatic transfer and automatic filming have been selected by the end of the operation, and in this event the operator has to return to the previous operating interface to check, which leads to more unnecessary clicks and lowers operational efficiency.
CT scanners known in the art can already meet requirements in terms of examination functions, but must be improved in terms of operational efficiency.